Results from the Swedish national anterior cruciate ligament register

Return to the Pre-Injury Level of Sport after Anterior Cruciate Ligament Reconstruction

Returning to sport after anterior cruciate ligament reconstruction (ACLR) can be a challenging and complex process for the athlete, with the rate of return to the pre-injury level of sport observed to be less than athlete expectations. Of the athletes that do return to sport (RTS), knee re-injury rates remain high, and multiple studies have observed impaired athletic performance upon RTS after ACLR as well as reduced playing time, productivity, and career lengths. To mitigate re-injury and improve RTS outcomes, multiple RTS after ACLR consensus statements/clinical practice guidelines have recommended objective RTS testing criteria to be met prior to medical clearance for unrestricted sports participation. While the achievement of RTS testing criteria can improve RTS rates after ACLR, current criteria do not appear valid for predicting safe RTS. Therefore, there is a need to review the various factors related to the successful return to the pre-injury level of sport after ACLR, clarify the utility of objective performance testing and RTS criteria, further discuss safe RTS decision-making as well as present strategies to reduce the risk of ACL injury/re-injury upon RTS. This article provides a practical review of the current RTS after ACLR literature, as well as makes medical recommendations for rehabilitation and RTS decision-making after ACLR.

Revision ACL reconstruction, but not bilateral ACL reconstruction, is associated with clinically relevant inferior subjective knee function compared with primary ACL reconstruction: A comparative analysis of 6831 patients

PURPOSE

To evaluate and compare the subjective knee function in patients undergoing revision and bilateral anterior cruciate ligament (ACL) reconstruction (ACLR) with those undergoing primary ACLR in a large cohort.

METHODS

Patients without concomitant ligament injuries who underwent primary, revision or bilateral ACLR at the Capio Artro Clinic, Stockholm, Sweden, between 2005 and 2018 were identified. The Knee injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and at 1, 2 and 5 years postoperatively from the Swedish National Knee Ligament Registry. Patients who underwent revision and bilateral ACLR were compared with those who underwent primary ACLR (control group) using Student's t test.

RESULTS

A total of 6831 patients (6102 with primary ACLRs, 343 with revision ACLRs and 386 with bilateral ACLRs) were included. Preoperatively, there were significant but nonclinically relevant differences in favour of the revision ACLR group for KOOS Symptoms, Pain, Activities of Daily Living (ADL) and Sport/Rec subscale scores compared with the primary ACLR group. Postoperatively, except for the 1-year Symptoms and ADL subscales, the revision ACLR group reported significantly lower scores on all KOOS subscales than the primary ACLR group, with clinically relevant differences (>8-10 points) for the 1-, 2- and 5-year Sport/Rec and Quality of Life (QOL) subscales. The bilateral ACLR group reported significantly, but not clinically relevant, inferior scores on the 1-year Symptoms and QOL subscales and the 5-year Sport/Rec and QOL subscales compared with the primary ACLR group.

CONCLUSIONS

Revision ACLR, but not bilateral ACLR, was associated with clinically relevant inferior subjective knee function compared with primary ACLR. It is important to counsel patients regarding their future subjective knee function after repeated ACLR. Compared to primary ACLR, inferior subjective results should be expected after revision ACLR, but not after bilateral ACLR.

LEVEL OF EVIDENCE

Level III.

Comparison of Outcomes Between a Fixed-Loop Cortical Suspensory Device and Metal Interference Screw for Femoral Fixation of Bone-Patellar Tendon-Bone Grafts in Anterior Cruciate Ligament Reconstruction: A Scandinavian Registry Study

Background

Use of a cortical suspensory device (CSD) is an alternative fixation method for bone-patellar tendon-bone (BPTB) in the femur. To the authors' knowledge, no study has compared revision outcomes and patient-reported outcomes (PROs) with the traditional interference screw (IS) fixation.

Purpose

To compare the survival rate of grafts fixated on the femoral side with either a fixed-loop CSD or IS for primary anterior cruciate ligament reconstructions (ACLRs) with BPTB autograft 2 and 5 years after index surgery, as well as to compare PROs between the same 2 treatment groups based on data from 3 National Knee Ligament Registers (NKLRs) in Scandinavia.

Study Design

Cohort study; Level of evidence, 2.

Methods

The study included patients registered in the NKLRs of Norway, Denmark, and Sweden who underwent primary ACLR from 2005 to 2021. Patients undergoing additional surgery for concomitant injuries to the posterior cruciate ligament, lateral collateral ligament, or medial collateral ligament and patients with major cartilage lesions were excluded. Cox regression models with and without adjustment for possible confounding from age, sex, meniscal and chondral injury, tibial fixation, surgical time, time from injury to surgery, injury mechanism, and country were used to calculate hazard ratios (HRs) and 95% confidence intervals. The possible effects of femoral fixation on 1-year postoperative KOOS QoL and on change from preoperative to 1-year postoperative KOOS QoL were analyzed using multiple linear regression with adjustment from possible confounding from the same variables. P values <.05 were considered significant.

Results

A total of 13,955 primary ACLRs met the inclusion criteria during the study period; 1852 patients (13%) had a femoral CSD fixation and 12,103 patients (87%) a femoral IS fixation. No significant difference was observed in overall risk of revision between CSD and IS (HR, 1.10; 95% CI, 0.83 to 1.47; P = .5), and differences in cumulative survival at 2 years (CSD: 98.3% vs IS: 98.6%) and 5 years (CSD: 96.3% vs IS: 96.4%) were not statistically significant. No difference was found for mean KOOS QoL delta (1 year minus baseline) when adjusting for possible confounders (mean difference, -1.60; 95% CI, -3.83 to 0.63; P = .16).

Conclusion

Data from the Scandinavian NKLRs showed no difference in the risk of revision and no difference in the KOOS QoL for fixed-loop CSD fixation compared with IS fixation on the femoral side with BPTB grafts in primary ACL reconstruction.

Several factors predict the achievement of the patient acceptable symptom state and minimal clinically important difference for patient-reported outcome measures following anterior cruciate ligament reconstruction: A systematic review

PURPOSE

To summarize the predictors of the patient acceptable symptom state (PASS), minimal clinically important difference (MCID) and minimal important change (MIC) for patient-reported outcome measures (PROMs) following anterior cruciate ligament reconstruction (ACLR).

METHODS

MEDLINE, PubMed and Embase were searched from inception to 5 January 2024. The authors adhered to PRISMA/R-AMSTAR guidelines, and the Cochrane Handbook for Systematic Reviews of Interventions. Data on statistical associations between predictive factors and PROMs were extracted. Inverse odds ratios (ORs) and confidence intervals (reverse group comparison) were calculated when appropriate to ensure comparative consistency.

RESULTS

Thirteen studies comprising 21,235 patients (48.1% female) were included (mean age 29.3 years). Eight studies comprising 3857 patients identified predictors of PASS, including lateral extra-articular tenodesis (LET) (OR = 11.08, p = 0.01), hamstring tendon (HT) autografts (OR range: 2.02-2.63, p ≤ 0.011), age over 30 (OR range: 1.37-2.28, p ≤ 0.02), male sex (OR range: 1.03-1.32, p ≤ 0.01) and higher pre-operative PROMs (OR range: 1.04-1.21). Eight studies comprising 18,069 patients identified negative predictors of MCID or MIC, including female sex (OR = 0.93, p = 0.034), absence of HT autografts (OR = 0.70, p < 0.0001), higher pre-operative PROMs (OR = 0.76-0.84, p ≤ 0.01), meniscectomy (OR = 0.67, p = 0.014) and collision sports (OR = 0.02-0.60, p ≤ 0.05).

CONCLUSION

Higher pre-operative PROMs, age over 30, male sex, LETs and HT autografts predicted PASS achievement. Lower pre-operative PROMs, male sex, non-collision sports, and lack of meniscectomies predicted MCID/MIC achievement. This review provides a comprehensive understanding of the predictors of clinically significant post-ACLR outcomes, thus improving clinical decision-making and the management of patient expectations.

LEVEL OF EVIDENCE

Level IV.

Symptoms indicative of early knee osteoarthritis after ACL reconstruction: descriptive analysis of the SHIELD cohort

Objective

To describe the SHIELD cohort in terms of symptoms indicative of early knee osteoarthritis (OA) and to investigate associations between patient characteristics (demographics, activity/injury-related) and these symptoms at 1 (cross-sectional) and 3 years (longitudinal) post anterior cruciate ligament reconstruction (ACLR).

Method

106 participants (50 ​% women, mean [SD] age 25 [5] years) were included. Symptoms indicative of early knee OA were evaluated by the Knee injury and Osteoarthritis Outcome Score (KOOS) subscale pain, KOOS subscale pain ≤72 (KOOSpain ≤72), and ≤85 on two out of four KOOS subscales (pain, symptoms, activity of daily living, quality of life) (modified Luyten).

Results

Mean (SD) KOOS pain scores were 83.2 (15.7) and 87.3 (12.7) at 1 and 3 years, respectively. At 1 year and 3 years post ACLR, 18/101 (18 ​%) and 14/86 (16 ​%) participants met the KOOSpain ≤72 criterion, whereas 83/101 (82 ​%) and 67/86 (78 ​%) met the modified Luyten criterion. 7/15 (47 ​%) (KOOSpain ≤72) and 59/70 (84 ​%) (modified Luyten) classified as having knee OA symptoms 1 year post ACLR were still classified as having OA symptoms after 3 years. Lower activity level at 1 year was the sole variable consistently associated with all three outcomes 3 years post ACLR.

Conclusion

The proportion of participants fulfilling existing classification criteria for symptoms indicative of early OA after ACLR is highly dependent on the criteria applied and different criteria seem to capture varying aspects of early OA symptoms. Future studies will reveal if these symptoms will persist long-term or just reflect more transient issues.

Primary Anterior Cruciate Ligament Reconstruction Performed With Hamstring Tendon Autograft Leads to an Over 4 Times Greater Rate of Second Anterior Cruciate Ligament Rupture After Return to Sport in Patients With Generalized Joint Hypermobility Compared With Bone-Patellar Tendon-Bone Autograft

PURPOSE

To examine the rate of (1) second anterior cruciate ligament (ACL) rupture (graft rupture or contralateral ACL rupture) and (2) graft rupture alone in patients with generalized joint hypermobility (GJH) at 12 months, at 24 months, and at the longest available time (LAT) following return to sport (RTS) after ACL reconstruction depending on graft choice, that is, hamstring tendon (HT) autograft or bone-patellar tendon-bone (BPTB) autograft.

METHODS

Data were extracted from a rehabilitation registry that comprised patients who had undergone ACL reconstruction between 2014 and 2022. Patients with GJH aged between 16 and 50 years who had minimum 24-month follow-up following RTS after ACL reconstruction with HT autograft (GJH-HT) or BPTB autograft (GJH-BPTB) were included. A Cox proportional hazard regression model was used to examine the rate of (1) second ACL rupture (graft rupture or contralateral ACL rupture) and (2) graft rupture alone at 12 months, at 24 months, and at the LAT after RTS.

RESULTS

This study included 82 patients (54 in the GJH-HT group and 28 in the GJH-BPTB group), of whom 72.0% were female patients, and the average age was 22.7 ± 7.4 years. The proportion of second ACL ruptures was greater in the GJH-HT group than in the GJH-BPTB group at 12 months (11 of 54 [20.4%] vs 0 of 28 [0%], P = .013), at 24 months (13 of 54 [24.1%] vs 1 of 28 [3.6%], P = .028), and at the LAT (16 of 54 [29.6%] vs 2 of 28 [7.1%], P = .024) after RTS. The rate of second ACL rupture was greater in the GJH-HT group than in the GJH-BPTB (hazard ratio = 4.98, P = .032) at the LAT after RTS. The proportion of patients with graft rupture was greater in the GJH-HT group than in the GJH-BPTB group at 12 months (8 of 54 [14.8%] vs 0 of 28 [0%], P = .046), at 24 months (10 of 54 [18.5%] vs 0 of 28 [0%], P = .013), and at the LAT (12 of 54 [22.2%] vs 0 of 28 [0%], P = .006) after RTS.

CONCLUSIONS

An over 4 times greater rate of second ACL rupture after RTS was reported for patients with GJH who underwent ACL reconstruction with HT autograft compared with BPTB autograft. Patients with GJH who were treated with BPTB autograft for ACL reconstruction did not experience graft rupture after RTS.

LEVEL OF EVIDENCE

Level III, retrospective study.

Return to competition after ACL reconstruction: Factors influencing rates and timing in Swedish football players

PURPOSE

To investigate the rate and timing for return to football league games after anterior cruciate ligament reconstruction (ACLR) in Swedish players, examining associations with sex, age, level, graft and additional ACL surgery.

METHOD

Data from the Swedish National Knee Registry (SNKLR) and the Swedish Football Association's IT System (FOGIS) were used. The study cohort comprised 971 football players, 64% males, who underwent primary ACLR. Demographics, graft type and surgical information were extracted from the SNKLR and game participation from FOGIS. Follow-up for return to competition (RTC) was conducted for 36 months, while additional ACLR follow-up was 3-7 years. Statistical analyses, including Kaplan-Meier survival curves and relative risk calculations, were employed to assess factors influencing RTC rates and timing.

RESULTS

Out of 971 players analyzed, 53% RTC within 3 years with no difference between males and females, at a mean of 15 months (median 14 months) from surgery to the first game. Eleven (2%) players RTC < 6 months from ACLR, 62 (12%) 6-9 months, 125 (24%) 9-12 months and 331 (63%) >12 months. Patellar tendon (PT) grafts demonstrated superior performance, showing quicker returns and higher RTC rates (p = 0.005) compared to hamstring (hazard ratio [HR]: 0.63 [0.48-0.84]) and quadriceps tendon grafts (HR: 0.53 [0.30-0.93]). Players competing in higher divisions pre-injury experienced significantly swifter and higher RTC rates (p < 0.001). Ninety-five (10%) had a registered additional ACLR. Players who RTC did not exhibit a significantly higher rate of revision (35 [7%] vs. 25 [5%]). However, those who returned faced a heightened risk of contralateral ACLRs compared to those who did not RTC (32 [6%] vs. 4 [1%] RR 1.72 [1.59-1.96], p < 0.001).

CONCLUSION

The study reveals that 53% of football players RTC after ACLR, predominantly after more than 12 months. The RTC was higher and faster in high-level players and those receiving a PT graft. The slow RTC may contribute to the relatively low rate of additional ACLRs.

LEVEL OF EVIDENCE

Level III.

Physiologic Preoperative Knee Hyperextension Is Not Associated With Postoperative Laxity, Subjective Knee Function, or Revision Surgery After ACL Reconstruction With Hamstring Tendon Autografts

BACKGROUND

There is concern that physiologic knee hyperextension may be associated with inferior outcomes after anterior cruciate ligament reconstruction (ACLR) using hamstring tendon (HT) autografts.

PURPOSE

To assess whether there is an association between contralateral passive preoperative knee hyperextension (≤-5°) and postoperative anterior knee laxity, subjective knee function, or revision surgery after ACLR using HT autografts.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients without concomitant ligament injuries who underwent primary ACLR using an HT autograft at Capio Artro Clinic, Stockholm, Sweden, between January 1, 2005, and December 31, 2018, were identified. The cohort was dichotomized into the hyperextension group (≤-5°) and the no hyperextension group (>-5°) depending on preoperative contralateral passive knee extension degree. Anterior knee laxity (KT-1000 arthrometer; 134 N) was assessed preoperatively and at 6 months postoperatively. The Knee injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and at 1, 2, and 5 years postoperatively. Patients who underwent revision ACLR at any institution in Sweden within 5 years of the primary surgery were identified in the Swedish National Knee Ligament Registry.

RESULTS

A total of 6104 patients (53.5% male) for whom knee range of motion measurements were available were identified (hyperextension group [≤-5°]: 2350 [38.5%]; mean extension, -6.1°± 2.3° [range, -20° to -5°]; no hyperextension group [>-5°]: 3754 [61.5%]; mean extension, 0°± 1.4° [range, -4° to 15°]). There were no intergroup differences in anterior knee laxity preoperatively (hyperextension group, 3.6 ± 2.8 mm; no hyperextension group, 3.7 ± 2.7 mm; P = .24) or postoperatively (hyperextension group, 1.8 ± 2.3 mm; no hyperextension group, 1.8 ± 2.2 mm; P = .41). The only significant but nonclinically relevant intergroup differences were seen in the KOOS Symptoms subscale at the 1-year follow-up (hyperextension group, 81.4 ± 16.0; no hyperextension group, 80.3 ± 16.5; P = .03) and in the Sport and Recreation subscale at the 5-year follow-up (hyperextension group, 73.0 ± 25.6; no hyperextension group, 75.7 ± 24.3; P = .02). No other significant intergroup differences were noted preoperatively or at 1, 2, or 5 years postoperatively in any of the KOOS subscales. The overall revision ACLR rate at ≤5 years after the primary surgery was 4.9% (302 of 6104 patients). The hazard for revision ACLR in the no hyperextension group (4.5%; 170 of 3754 patients) was not significantly different from that in the hyperextension group (5.6%; 132 of 2350 patients) (hazard ratio, 0.89; 95% CI, 0.71 to -1.12; P = .34). A subsequent subanalysis showed that the hazard of revision ACLR in patients with no hyperextension was not significantly different from that of patients with ≤-10° of extension (5.8%; 27 of 467 patients) (hazard ratio, 0.91; 95% CI, 0.61 to 1.36; P = .65).

CONCLUSION

Preoperative passive contralateral knee hyperextension (≤-5°) was not associated with postoperative anterior knee laxity, subjective knee function, or revision surgery ≤5 years after ACLR using HT autografts. Therefore, the presence of knee hyperextension alone should not be considered a contraindication per se for the use of HT autografts in ACLR.

Lower Surgical Volume Reduces the Odds of Performing Meniscus Repair for Tears During Primary Anterior Cruciate Ligament Reconstruction

PURPOSE

To investigate the influence of surgical volume, and various patient-, injury-, and surgery-related factors, on meniscal treatment strategies in primary anterior cruciate ligament reconstruction (ACLR).

METHODS

This retrospective cohort study analyzed patients with concomitant meniscal injuries undergoing primary ACLR, from 2008 to 2022, using data from the Swedish National Knee Ligament Registry. Surgeons and clinics were stratified by total caseload (cutoff: 50 ACLRs/surgeon, 500 ACLRs/clinic) and annual volume (cutoff: 29 ACLRs/year/surgeon, 56 ACLRs/year/clinic). To assess factors influencing medial meniscus or lateral meniscus repair, adjusted multivariable logistic regression was conducted, with results presented as odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

In total, 20,699 patients undergoing primary ACLR with concomitant meniscal injuries were included. Lower percentages of meniscus repair were seen among surgeons with low caseload and annual volume (LCLV) (13.3%-20.8%) compared with high caseload and annual volume (HCHV) surgeons (19.0%-29.8%), and at LCLV clinics (11.1%-18.3%) compared to HCHV clinics (21.5%-33.8%), all P < .001. Significantly decreased odds of medial meniscus repair were seen for patients operated on by LCLV surgeons (OR 0.82, 95% CI 0.70-0.96; P = .015) or at LCLV clinics (OR 0.56, 95% CI 0.50-0.64; P < .001. Similar results were seen for lateral meniscus repair with LCLV surgeons (OR 0.83, 95% CI 0.69-1.01; P = .067) and LCLV clinics (OR 0.62, 95% CI 0.53-0.72; P < .001). Additionally, younger age, female sex, shorter time from injury to surgery, and ACLRs performed more recently were associated with increased odds of repair.

CONCLUSIONS

Lower surgical volume significantly decreased the rates and odds of performing meniscal repair during primary ACLR. In contrast, ACLRs performed during more recent years, younger age, female sex, shorter time from injury to surgery, absence of chondral injuries, and injuries sustained during nonpivoting activities, positively influenced meniscal preservation.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Analysis of the Swedish Knee Ligament Register: Concomitant injuries, revision surgery and smoking render worse results

PURPOSE

To analyse the 52,199 patients in the Swedish Knee Ligament Register (SKLR) preoperatively, and the patients reaching 5- and 10-year follow-ups who underwent anterior cruciate ligament reconstruction (ACLR), revision ACLR and ACLR on the contralateral side (CACLR). The main hypothesis was that patients undergoing revision ACLR would have worse patient-reported outcome measurements (PROMs) than the primary ACLR group at 10 years and that smoking and concomitant injuries would result in poorer outcomes for all groups.

METHODS

Data from 2005 to 2021 were extracted from the SKLR. Only patients whose ACLR surgery was registered in the SKLR were included for revision ACLR and CACLR. The PROMs consist of the Knee injury and Osteoarthritis Outcome Score (KOOS) and the knee-specific PROM (EQ-5D-3L). PROMs were analysed as a whole and in subgroups based on sex, smoking, graft choice and concomitant injuries.

RESULTS

Poorer KOOS were seen for revisions compared with primary ACLRs at both the 5- and 10-year follow-ups (p = 0.003). Smokers had significantly poorer KOOS than nonsmokers (p < 0.001) preoperatively in all groups, however only in the primary ACLR group at 5 and 10 years. At 10 years, patients who had undergone CACLR had lower KOOS than primary ACLRs (p = 0.03). Concomitant injuries resulted in statistically, significantly poorer KOOS for both primary ACLRs and CACLRs preoperatively and at the follow-ups.

CONCLUSION

The PROMs for revision ACLRs have worse KOOS scores at 10 years compared with the primary ACLRs. The presence of concomitant meniscal or cartilage injuries at the time of ACLR or CACLR were associated with worse PROMs.

LEVEL OF EVIDENCE

Level III.

Validating the capture rate of revisions by the New Zealand ACL Registry: An analysis of all-cause reoperation following primary ACL reconstruction

PURPOSE

To validate the New Zealand Anterior Cruciate Ligament (ACL) Registry's capture rate of revisions by cross-referencing Registry data with reoperations data recorded by the Accident Compensation Corporation (ACC) and identify risk factors for all-cause reoperation.

METHODS

Primary ACL reconstructions performed between April 2014 and September 2019 were individually matched on a record-by-record basis between the two databases. The ACC database was used to identify patients who underwent a reoperation with manual review of operation notes to identify whether a revision or other procedure was performed. This was combined with the number of revisions separately recorded in the New Zealand ACL Registry, which was used as the denominator value to calculate the Registry's capture rate of revisions. Patient and surgical data recorded in the Registry were analysed to identify independent predictors for all-cause reoperation.

RESULTS

A total of 8046 primary ACL reconstructions were matched between the New Zealand ACL Registry and the ACC databases. The reoperation rate was 8.9% (n = 715) at a mean follow-up of 2.5 years. Meniscal-related procedures were the most common reoperation (n = 299, 3.7%), followed by revision ACL reconstruction (n = 219, 2.7%), arthrofibrosis (n = 185, 2.3%), cartilage (n = 56, 0.7%) and implants (n = 32, 0.4%). The New Zealand ACL Registry captured 96% of revisions. Younger age (hazard ratio [HR] > 1.4, p < 0.001), earlier surgery (HR > 1.3, p = 0.05), concurrent meniscal repair (medial meniscus HR = 1.9, p < 0.001 and lateral meniscus HR = 1.3, p = 0.022) and hamstring tendon autografts (HR = 1.4, p = 0.001) were associated with a higher risk of reoperation.

CONCLUSION

The New Zealand ACL Registry captured 96% of revisions. Risk factors for all-cause reoperation included younger age, earlier surgery, meniscal repair and hamstring tendon autografts.

LEVEL OF EVIDENCE

Level III.

Diagnosis and treatment of anterior cruciate ligament injuries: Consensus of Chinese experts part II: Graft selection and clinical outcome evaluation

Background

In the recent decade, there has been substantial progress in the technologies and philosophies associated with diagnosing and treating anterior cruciate ligament (ACL) injuries in China. The therapeutic efficacy of ACL reconstruction in re-establishing the stability of the knee joint has garnered widespread acknowledgment. However, the path toward standardizing diagnostic and treatment protocols remains to be further developed and refined.

Objective

In this context, the Chinese Association of Orthopaedic Surgeons (CAOS) and the Chinese Society of Sports Medicine (CSSM) collaboratively developed an expert consensus on diagnosing and treating ACL injury, aiming to enhance medical quality through refining professional standards.

Methods

The consensus drafting team invited experts across the Greater China region, including the mainland, Hong Kong, Macau, and Taiwan, to formulate and review the consensus using a modified Delphi method as a standardization approach. As members of the CSSM Lower Limb Study Group and the CAOS Arthroscopy and Sports Medicine Study Group, invited experts concentrated on two pivotal issues: "Graft Selection" and "Clinical Outcome Evaluation" during the second part of the consensus development.

Results

This focused discussion ultimately led to a strong consensus on nine specific consensus terms.

Conclusion

The consensus clearly states that ACL reconstruction has no definitive "gold standard" graft choice. Autografts have advantages in healing capability but are limited in availability and have potential donor site morbidities; allografts reduce surgical trauma but incur additional costs, and there are concerns about slow healing, quality control issues, and a higher failure rate in young athletes; synthetic ligaments allow for early rehabilitation and fast return to sport, but the surgery is technically demanding and incurs additional costs. When choosing a graft, one should comprehensively consider the graft's characteristics, the doctor's technical ability, and the patient's needs. When evaluating clinical outcomes, it is essential to ensure an adequate sample size and follow-up rate, and the research should include patient subjective scoring, joint function and stability, complications, surgical failure, and the return to sport results. Medium and long-term follow-ups should not overlook the assessment of knee osteoarthritis.

Anterior Cruciate Ligament Tears in Soccer Players

Anterior cruciate ligament (ACL) injuries to soccer players present unique challenges in sports medicine, given the sport's global prevalence and intricate injury dynamics. These injuries, especially in the youth and female demographic, have become a substantial concern in sports medicine. This review explores the epidemiology, mechanism of injury, diagnostic procedures, treatment modalities, and rehabilitation strategies related to ACL tears within the soccer community. Progress in diagnostics, treatments, and rehabilitation underscores the importance of evidence-based approaches. As soccer continues its ascent in popularity, addressing the specific risks and nuances of ACL injuries in this context remains of paramount significance.

Registry-based cohort study comparing percentages of patients reaching PASS for knee function outcomes after revision ACLR compared to primary ACLR

OBJECTIVES

Reaching the Patient-Acceptable Symptom State (PASS) threshold for the Knee injury and Osteoarthritis Outcome Score (KOOS) has previously been reported to successfully identify individuals experiencing clinical success after anterior cruciate ligament reconstruction (ACLR). Thus, the objectives of this study were to examine and compare the percentages of patients meeting PASS thresholds for the different KOOS subscales 1 year postoperatively after primary ACLR compared with revision ACLR (rACLR) and multiply revised ACLR (mrACLR), and second, to examine the predictors for reaching PASS for KOOS Quality of Life (QoL) and Function in Sport and Recreation (Sport/Rec) after mrACLR.

DESIGN

Prospective observational registry study.

SETTING

The data used in this study was obtained from the Swedish National Ligament Registry and collected between 2005 and 2020.

PARTICIPANTS

The study sample was divided into three different groups: (1) primary ACLR, (2) rACLR and (3) mrACLR. Data on patient demographic, injury and surgical characteristics were obtained as well as mean 1-year postoperative scores for KOOS subscales and the per cent of patients meeting PASS for each subscale. Additionally, the predictors of reaching PASS for KOOS Sport/Rec, and QoL subscales were evaluated in patients undergoing mrACLR.

RESULTS

Of the 22 928 patients included in the study, 1144 underwent rACLR and 36 underwent mrACLR. Across all KOOS subscales, the percentage of patients meeting PASS thresholds was statistically lower for rACLR compared with primary ACLR (KOOS Symptoms 22.5% vs 32.9%, KOOS Pain 84.9% vs 92.9%, KOOS Activities of Daily Living 23.5% vs 31.4%, KOOS Sport/Rec 26.3% vs 45.6%, KOOS QoL 26.9% vs 51.4%). Percentages of patients reaching PASS thresholds for all KOOS subscales were comparable between patients undergoing rACLR versus mrACLR. No predictive factors were found to be associated with reaching PASS for KOOS QoL and KOOS Sport/Rec 1 year postoperatively after mrACLR.

CONCLUSION

Patients undergoing ACLR in the revision setting had lower rates of reaching acceptable symptom states for functional knee outcomes than those undergoing primary ACLR.

LEVEL OF EVIDENCE

Prospective observational registry study, level of evidence II.

Young men undergoing anterior cruciate ligament reconstruction with patellar tendon autograft and anteromedial drilling outperform at 5- to 10-year follow-up in terms of graft stability and activity levels compared to those undergoing reconstruction with hamstring autograft and transtibial drilling

OBJECTIVE

To compare 5- to 10-year outcomes of anterior cruciate ligament (ACL) reconstruction in young men performed with bone-patellar tendon bone (BPTB) autograft and anteromedial portal to reconstruction with hamstring autograft and transtibial technique. It was hypothesised that in young adult men, at 5- to 10-year follow-up, superior restoration of knee laxity and activity levels would be demonstrated using BPTB autograft and anteromedial portal technique.

METHODS

Ninety-four men who had ACL reconstruction with BPTB autograft and anteromedial portal were eligible for comparison to 106 men who had reconstruction with hamstring autograft and transtibial technique. Inclusion criteria were: (1) age 18-35 years, (2) ACL tear caused by sports trauma only, (3) no concomitant ligament reconstruction and (4) 5- to 10-year follow-up. Outcome measures compared between the two groups included Lachman and pivot shift tests, KT side-to-side difference, Tegner and Marx scores, International Knee Documentation Committee (IKDC)-subjective score, Knee Osteoarthritis Outcome Scale (KOOS), Short Form (SF)-36, and single hop test for distance. P value ​< ​0.05 indicated statistical significance.

RESULTS

Forty-five patients with BPTB and 55 patients with hamstring ACL reconstruction were available for in-person assessment at 5-10 years after surgery. Outcomes in the BPTB group compared to the hamstring group showed KT difference 1.4 ​± ​1.9 mm vs. 2.8 ​± ​2.3 mm (p ​< ​0.01), pivot shift grade 2-3 in 4% vs. 34% (p ​< ​0.01), return to preinjury Tegner level in 51% vs. 36% (p ​= 0.1) and to preinjury Marx score in 29% vs. 11% (p ​= 0.02), and IKDC-subjective 88 ​± ​10 vs. 82 ​± ​13 vs (p ​< ​0.01), respectively. Statistically significant inter-relationships were found between KT side-to-side difference and the Tegner, Marx and IKDC-subjective scores at follow-up (r ​= ​-0.314, p ​< ​0.01; r ​= ​-0.263, p ​< ​0.01; r ​= ​-0.218, p ​= ​0.03, respectively).

CONCLUSION

Young men undergoing ACL reconstruction with patellar tendon autograft and anteromedial drilling outperform at 5- to 10-year follow-up in terms of graft stability and activity levels compared to young men undergoing reconstruction with hamstring autograft and transtibial drilling.

LEVEL OF EVIDENCE

III (Retrospective cross-sectional comparative study).

Low meniscus reoperation rates following meniscus repair during anterior cruciate ligament reconstruction in Turkey: an in-depth national analysis of 8-years

BACKGROUND

Concomitant knee injuries, such as meniscal tears, are observed in up to 80% of cases and can have a detrimental impact on outcomes following anterior cruciate ligament reconstruction (ACLR). Over recent decades, there has been a growing recognition of the importance of preserving meniscal tissue. Consequently, the prevalence of meniscal-preserving procedures has been on the rise.

PURPOSE

The objective of this study was to examine the prevalence of concurrent meniscal procedures, assess the success rate, and identify factors associated with the failure of meniscal repair in patients undergoing ACLR.

METHODS

All patients who underwent ACLR due to anterior cruciate ligament (ACL) injury between January 2015 and December 2022 were extracted from the Republic of Türkiye National health system using operation-specific procedure codes. Patients with multiple ligament injuries, revision ACL patients, and patients with missing data were excluded from the study. The treatment methods were grouped into the subsets of meniscectomy, meniscal repair, transplantation, and meniscectomy + repair. The distribution of ACLR and meniscus treatment methods according to years, age and sex groups, hospital characteristics, and geographical regions was examined. A secondary analysis was performed to assess the effect of patient demographics and hospital healthcare level on revision meniscal procedures in the ACLR + concomitant meniscal repair group.

RESULTS

A total of 91,700 patients who underwent ACLR between 2015 and 2022 were included in the study. A concomitant meniscal procedure was noted in 19,951(21.8%) patients (16,130 repair,3543 meniscectomy). In the 8 years studied, meniscus repair rates increased from 76.3%to87.9%, while meniscectomy rates decreased from 23.7%to12.1% (p < 0.001). The revision meniscus surgery rate following ACLR + meniscal repair was 3.7%at a mean follow-up of 50 ± 26 months. The interval between primary and revision surgery was 20.5 ± 21.2 months. The meniscectomy rates were higher in community hospitals, while private hospitals showed the lowest revision meniscus surgery rates. Younger age was associated with increased meniscus repair failure rates.

CONCLUSION

The propensity towards using repair techniques to treat meniscal tears during concurrent ACLR has significantly increased in Turkey. Age and the healthcare level of the treating hospital affect the success of meniscal repair.

A High Grade of Postoperative Knee Laxity Is Associated With an Increased Hazard of Revision Surgery: A Cohort Study of 4697 Patients With Primary ACL Reconstruction

BACKGROUND

There is still debate regarding the association between arthrometric knee laxity measurements and subjective knee outcome and revision surgery after primary anterior cruciate ligament reconstruction (ACLR).

PURPOSE

To assess whether arthrometric knee laxity (measured with the KT-1000 arthrometer) 6 months after primary ACLR was associated with the 1-, 2-, and 5-year subjective knee outcomes or revision ACLR at a 5-year follow-up.

STUDY DESIGN

Cohort study, Level of evidence 3.

METHODS

Patients who underwent primary ACLR with a hamstring tendon autograft at the authors' institution between January 1, 2005, and December 31, 2017, with no concomitant ligamentous injuries, were identified. Anterior knee laxity (KT-1000 arthrometer, 134 N) was assessed 6 months postoperatively. The Knee injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and 1, 2, and 5 years postoperatively. Patients who underwent revision ACLR at any institution in the country within 5 years of primary surgery were identified through the Swedish National Knee Ligament Registry.

RESULTS

A total of 4697 patients (54.3% male) with available KT-1000 arthrometer measurements were included (normal: side-to-side [STS] ≤2 mm, 3015 [64.2%]; nearly normal: STS 3-5 mm, 1446 [30.8%]; abnormal: STS >5 mm, 236 [5.0%]). The only significant difference in subjective knee outcome between the groups was for the KOOS Symptoms subscale at the 1-year follow-up (STS ≤2 mm, 79.9 ± 16.2; STS 3-5 mm, 82.5 ± 14.8; STS >5 mm, 85.1 ± 14.2; P < .001). No other significant differences between the groups were found preoperatively or at 1, 2, or 5 years postoperatively for any of the KOOS subscales. The hazard for revision ACLR within 5 years of the primary surgery was significantly higher for the groups with an STS of 3 to 5 mm (6.6%; 95/1446) (hazard ratio [HR], 1.42; 95% CI, 1.07-1.87; P = .01) and an STS >5 mm (11.4%; 27/236) (HR, 2.61; 95% CI, 1.69-4.03; P < .001) compared with the group with an STS ≤2 mm (3.8%; 116/3015).

CONCLUSION

A high grade of postoperative knee laxity (STS 3-5 mm and STS >5 mm) 6 months after primary ACLR was associated with an increased hazard of revision ACLR within 5 years, but it was not associated with an inferior subjective knee outcome.

Return to the Pre-Injury Level of Sport after Anterior Cruciate Ligament Reconstruction: A Practical Review with Medical Recommendations

Returning to sport after anterior cruciate ligament reconstruction (ACLR) can be a challenging and complex process for the athlete, with the rate of return to the pre-injury level of sport observed to be less than athlete expectations. Of the athletes that do return to sport (RTS), knee re-injury rates remain high, and multiple studies have observed impaired athletic performance upon RTS after ACLR as well as reduced playing time, productivity, and career lengths. To mitigate re-injury and improve RTS outcomes, multiple RTS after ACLR consensus statements/clinical practice guidelines have recommended objective RTS testing criteria to be met prior to medical clearance for unrestricted sports participation. While the achievement of RTS testing criteria can improve RTS rates after ACLR, current criteria do not appear valid for predicting safe RTS. Therefore, there is a need to review the various factors related to the successful return to the pre-injury level of sport after ACLR, clarify the utility of objective performance testing and RTS criteria, further discuss safe RTS decision-making as well as present strategies to reduce the risk of ACL injury/re-injury upon RTS. This article provides a practical review of the current RTS after ACLR literature, as well as makes medical recommendations for rehabilitation and RTS decision-making after ACLR.

Functional outcomes in single stage bilateral ACL reconstruction with a maximum follow up of 10 years

Background

Bilateral ACL injuries are a rarity and there is no particular consensus on whether this rare problem has to be tackled in stages or in a single stage. There are a few studies and case reports in the literature about the outcomes in single staged bilateral Anterior cruciate ligament reconstruction (ACLR). This study is focused on functional outcomes after a single staged bilateral ACLR, as well as impact of simultaneity of the injury, meniscal tears, notch stenosis and hyperlaxity.

Materials and methods

A retrospective study was conducted from 2013 to 2021. Patients with bilateral ACL injury either simultaneous or non simultaneous, with or without meniscal tears were included in this study. Pre operative diagnosis was made both clinically and by MR imaging. All patients underwent a single staged bilateral ACL reconstruction. Pre operative functional scores (IKDC and Lysholm) were taken at admission and patients were examined at regular follow ups. Final functional scores were collected in a phone interview.

Results

33 patients underwent bilateral ACLR in a single stage during the study period but one patient had revision ACLR in one knee and so was excluded. Of the 32 patients, 25 (78%) had non simultaneous injury and 7 (22%) had a simultaneous injury, meniscus tear was noted in 27 (84.4%), notch stenosis in 19 (59.3%) and hyperlaxity in 12 (37.5%). IKDC and Lysholm scores have improved postoperatively. No statistically significant difference was found with or without simultaneous injury or meniscus tears.

Conclusion

Single stage bilateral ACL reconstruction is a safe, reproducible approach to bilateral ACL injuries whether they were simultaneous or non simultaneous or with or without meniscal tears.

Editorial Commentary: Gracilis-Sparing Anterior Cruciate Ligament Hamstring Graft Reconstruction Is Less Invasive Than Semitendinosus-Gracilis Graft Harvest, and Shows No Clinical Difference in Outcomes With Grafts Greater Than 8 mm in Diameter

Although patellar tendon grafts are most commonly used for anterior cruciate ligament reconstruction in the United States, hamstring autograft is most commonly used worldwide. Hamstring advantages include easy, quick harvest; low morbidity; ease of rehabilitation (compared with patellar tendon grafts); and relatively less pain. Historically, both the semitendinosus (ST) and gracilis are harvested, but by doubling, tripling, or quadrupling the ST to achieve an 8-mm graft, the gracilis can be spared, resulting in less knee flexion weakness. However, recent research has shown no clinically important difference between ST and ST-gracilis patient outcomes.

The Addition of the Gracilis Tendon to a Semitendinosus Tendon Autograft Is Not Associated With Knee Muscle Strength, Subjective Knee Function, or Revision Surgery After Anterior Cruciate Ligament Reconstruction

PURPOSE

To evaluate and compare isokinetic knee muscle (extension and flexion) strength, single-leg hop (SLH) test performance, anterior knee laxity, subjective knee function, and the 2-year revision surgery risk between patients who underwent anterior cruciate ligament reconstruction (ACLR) with semitendinosus tendon (ST) autografts and patients who underwent ACLR with ST and gracilis tendon (ST-G) autografts.

METHODS

We identified patients aged 16 years or older who underwent primary ACLR with hamstring tendon autografts at our institution from January 2005 to December 2020 and had no associated ligament injuries. Isokinetic knee muscle strength and SLH test performance were assessed 6 months postoperatively. Anterior knee laxity (KT-1000 arthrometer, 134 N) was assessed preoperatively and 6 months postoperatively. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and 1 and 2 years postoperatively. Patients who underwent revision ACLR at any institution in Sweden within 2 years of primary surgery were identified through the Swedish National Knee Ligament Registry.

RESULTS

A total of 6,974 patients (5,479 with ST and 1,495 with ST-G) were included. There were no significant differences in extension and flexion strength or SLH test performance between the groups. Preoperatively, there was no significant difference in knee laxity between the ST and ST-G groups. Postoperatively, the ST-G group had significantly increased mean side-to-side (STS) laxity (2.1 ± 2.3 mm vs 1.7 ± 2.2 mm, P < .001) and showed a trend toward increased STS laxity according to the International Knee Documentation Committee form, with significantly fewer patients with STS laxity of 2 mm or less (58.4% vs 65.8%) and significantly more patients with STS laxity between 3 and 5 mm (35.0% vs 29.9%) or greater than 5 mm (6.6% vs 4.3%) (P < .001). The only significant difference in subjective knee function was for the KOOS Quality of Life subscale score in favor of the ST group preoperatively (37.3 ± 21.4 vs 35.1 ± 19.9, P = .001). No other significant differences between the groups were found preoperatively and 1 and 2 years postoperatively for any of the KOOS subscales. The overall revision ACLR rate within 2 years of primary surgery was 2.0% (138 of 6,974 patients). The revision ACLR risk in the ST-G group (1.7%, 25 of 1,495 patients) was not significantly different from that in the ST group (2.1%, 113 of 5,479 patients) (hazard ratio, 0.80; 95% confidence interval, 0.50-1.24; P = .32).

CONCLUSIONS

The addition of the gracilis tendon to an ST autograft was not associated with knee muscle strength, SLH test performance, subjective knee function, or the risk of revision surgery after ACLR.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Return to Sport After Pediatric Anterior Cruciate Ligament Reconstruction: A Systematic Review of the Criteria

BACKGROUND

Postoperative rehabilitation is an important component of recovery after anterior cruciate ligament (ACL) reconstruction (ACLR), facilitating successful return to sport (RTS) by reducing risk factors for repeat injury.

PURPOSE

This systematic review aimed to determine the best protocol for RTS after ACLR in children.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

PubMed, Embase, PEDro, SPORTDiscus, and Web of Science databases were searched from October 3, 2014, to November 3, 2022. The inclusion criteria were the pediatric population (<18 years old) after ACLR with clear RTS criteria and/or mean/median time to RTS. Multiligament knee injuries were excluded from this study. The methodologic quality of the included articles was assessed using the methodological index for non-randomized studies (MINORS). The highest possible score was 24 points for comparative studies (ie, a study comparing 2 protocols or more). Noncomparative studies or studies with a single protocol could score a maximum of 16 points as assessed by the MINORS score.

RESULTS

The search yielded 1816 titles, and 24 were retained based on the inclusion and exclusion criteria. Every study was published between 2015 and 2022. Among the 24 studies included, 13 were retrospective and 11 were prospective. The mean MINORS score for the noncomparative studies was 13 of 16 (n = 23) and 23 of 24 for the comparative study (n = 1). The studies were categorized into unspecified clearance (n = 10), milestone based (n = 13), and combined time and milestone (n = 1). A total of 1978 patients (57% female) were included in the review. The mean age at ACLR was 14.7 years. The most common endpoint used was graft rupture (0% to 35%). In the unspecified group, the quickest RTS was 5.8 months and the longest was 9.6 months. Statistically significant risk factors for ACL reinjury included younger age and earlier RTS. The latter was a significant contributor to graft failure for combined time-based and milestone-based RTS. In the milestone-based group, the most common criteria were ≥90% limb symmetry measured using hamstring strength, quadriceps strength, and/or hop tests. The mean RTS time was 6.8 to 13.5 months.

CONCLUSION

RTS should be delayed, when possible, especially in the younger population. A combination of quantitative tests and qualitative tests is also recommended. However, optimal RTS criteria have yet to be determined. Future prospective studies should focus on comparing the different times and milestones currently available.

Comparison of Functional Outcomes after Anterior Cruciate Ligament Reconstruction with Meniscal Repair for Unstable versus Stable Meniscal Tears

This study aimed to compare functional outcomes including knee muscle strength in the quadriceps and hamstrings, and proprioception, assessed through dynamic postural stability (overall stability index [OSI]) and self-reported outcomes in the operated and non-operated knees between anterior cruciate ligament reconstruction (ACLR) with meniscal repair for unstable (root and radial tears) and stable (longitudinal, horizontal, and bucket handle tears) meniscal tears. A total of 76 patients were randomly selected (41 with ACLR with meniscal repair for unstable meniscal tears and 35 with ACLR with meniscal repair for stable meniscal tears) at three different time points (preoperative, 6 months, and 12 months). Repeated measures analysis of variance was used to investigate the differences in outcomes for between-subject and within-subject factors. In the operated knees, there were no significant differences for functional outcomes between the two groups (all p > 0.05). In the non-operated knees, a significant difference was observed for the OSI between the two groups, which was significantly higher in ACLR with meniscal repair for unstable meniscal tears than for stable meniscal tears at 6 months (p < 0.001). Multiple linear regression analysis showed that age (p = 0.027), preoperative OSI in the operated knees (p = 0.005), and postoperative OSI in the operated knees at 6 months (p = 0.002) were significant and independent predictors for OSI in the non-operated knees at 6 months postoperatively. Therefore, while no differences were observed in functional outcomes between the two groups in the operated knees, dynamic postural stability was poorer at 6 months postoperatively in the non-operated knees of patients with ACLR with meniscal repair for unstable meniscal tears. Furthermore, a significant correlation was observed between preoperative/postoperative dynamic postural stability in the operated knees and postoperative dynamic postural stability in the non-operated knees. Hence, we recommend incorporating balance exercises for both knees in post-surgical rehabilitation, particularly for patients with unstable meniscal tears.

Satisfactory 5-year functional outcomes following primary ACL reconstructions from the UK National Ligament Registry

PURPOSE

The aim of this study was to describe the 10-year findings from the UK National Ligament Registry (NLR).

METHODS

A retrospective review was performed for prospectively collected data on the NLR between January 2013 and December 2022. All patients who underwent primary ACL reconstruction (ACLR) on the registry were included. Surgical characteristics were analysed, including surgeon grade and case volume, concomitant knee procedures, venous thromboembolic prophylaxis, graft characteristics, femoral and tibial tunnel drilling, and fixation methods. Clinical outcomes were collected preoperatively and at 6 months, 1 year, 2 years and 5 years following the index procedure.

RESULTS

During the study period, 17,492 unilateral ACLR procedures were recorded. Autograft was used in 98%, most commonly a combined semitendinosus and gracilis graft (77%) or patella tendon graft (31%). Allograft was used in only 1% of the patients. In 52% of cases, ACLR was associated with an additional procedure, with isolated medial meniscal surgery being the most common (21%). Femoral tunnel drilling was mostly performed through an anteromedial portal (73%) and tibial tunnel drilling using an outside-in technique (92%). The most common method of femoral graft fixation was with an Endobutton fixed loop suspensory device (77%), while interference screws predominated for tibial tunnel fixation (86%). Patients who underwent ACLR surgery showed significant improvement in their functional outcome scores at six months, 1 year, 2 years and 5 years postoperatively.

CONCLUSION

Data from the NLR shows a detailed description of the current trends and evolution of ACLR in the United Kingdom over the last 10 years. Satisfactory functional outcomes were observed 5 years postoperatively. This study provides useful information on the prevalence of ACL-associated injuries and current surgical techniques with the aim of improving the quality of clinical care and patients' outcomes. Moreover, it provides surgeons with a benchmark against which to compare current practices and functional outcomes following ACLR across the United Kingdom.

LEVEL OF EVIDENCE

Level III.

Ten-year results from the UK National Ligament Registry: Patient characteristics and factors predicting nonresponders for completion of outcome scores

PURPOSE

The aim of this study was to report the demographic and mechanism of injury data in the UK National Ligament Registry (NLR) at 10 years and determine factors leading to poor compliance with completion of Patient-Reported Outcome Scores (PROMs).

METHODS

A retrospective review was performed for prospectively collected data on the NLR between January 2013 and December 2022. All patients who underwent primary anterior cruciate ligament reconstruction (ACLR) were included. Patient demographics, mechanism of injury and patient compliance with completing PROMs were analysed. Patient characteristics were further analysed in relation to compliance with completing the different PROMs at the predefined time points. Patients were identified as nonresponders if they had not completed either 1- or 2-year postoperative Knee injury and Osteoarthritis Outcome Score (KOOS).

RESULTS

A total of 17,492 patients were included in this study. The average age for patients undergoing ACLR between 2013 and 2022 was 29.4 (SD, 10.3). Seventy percent were men and 30% women. Football was the most common activity associated with an ACL injury. Patient compliance with recording PROMs was 55% preoperatively and 37%, 32% and 24% at 1-, 2- and 5-year postoperative follow-up, respectively. Nonresponders represented 54% of eligible patients. Multivariate analyses showed that sex, age, smoking, time interval between injury and surgery and low socioeconomic status were associated with low compliance with postoperative PROM completion (p < 0.001).

CONCLUSION

This study reports the demographic characteristics for patients on the NLR since 2013. Male sex, young age, increased waiting time between injury and surgery, smoking and lower socioeconomic class were predictors of low compliance with completion of postoperative PROMs on the UK NLR. Understanding the factors that affect patient compliance with PROMs improves our ability to provide targeted interventions and information to specific patient populations with the aim of enhancing inclusiveness and representation of population in the registry.

LEVEL OF EVIDENCE

Level III.

Influence of Surgeon Experience and Clinic Volume on Subjective Knee Function and Revision Rates in Primary ACL Reconstruction: A Study from the Swedish National Knee Ligament Registry

Background

Anterior cruciate ligament reconstruction (ACLR) performed by high-volume surgeons/clinics has been associated with increased graft individualization and decreased operating times, complication rates, and total costs.

Purpose

To investigate the influence of surgeon/clinic volume on subjective knee function and revision surgery rates at 2 years after primary ACLR.

Study Design

Cohort study; Level of evidence, 3.

Methods

Data from the Swedish National Knee Ligament Registry were used to study patients who underwent primary ACLR between 2008 and 2019. Surgeons/clinics were categorized based on a combination of total caseload volume (cutoff: 50 ACLRs/surgeon, 500 ACLRs/clinic) and annual volume (cutoff: 29 ACLRs/year/surgeon, 56 ACLRs/year/clinic). The thresholds of minimal important change (MIC), Patient Acceptable Symptom State (PASS), and treatment failure (TF) relative to the Knee injury and Osteoarthritis Outcome Score (KOOS) and KOOS4 (mean score of the KOOS Pain, Symptoms, Sports/Rec, and QoL subscales) were applied. Adjusted multivariable logistic regression was performed to assess variables influencing the MIC, PASS, or TF of the KOOS and KOOS4. Adjusted Cox regression analysis was conducted to determine the hazard ratio of subsequent ACLR.

Results

Of 35,371 patients, 16,317 had 2-year follow-up outcome data and were included. Patients who underwent primary ACLR by high-volume surgeons had significantly higher MIC and PASS rates and lower TF rates when compared with patients who underwent the procedure by low-volume surgeons: MICKOOS4: 70.6% vs 66.3%; PASSKOOS4: 46.0% versus 38.3%; and TFKOOS4: 8.7% versus 11.8% (all P < .02). Significantly decreased odds of achieving MICKOOS4 (OR, 0.74; 95% CI, 0.62-0.88) and PASSKOOS4 (OR, 0.71; 95% CI, 0.60-0.84) were found for ACLRs performed by low-volume surgeons. Clinic volume did not influence the odds of reaching MIC, PASS, or TF. Overall, 804 patients (2.3%) underwent subsequent ACLR at <2 years, with significantly higher revision rates among patients operated on at high-volume clinics (2.5% vs 1.7%; P < .001). However, in the adjusted Cox regression, surgeon/clinic volume had no influence on subsequent ACLR rates. High-volume surgeons/clinics had decreased time to surgery, operating time, perioperative complication rates, and use of thromboprophylaxis and nonroutine antibiotics (P < .001).

Conclusion

Patients who underwent primary ACLR by high-volume surgeons experienced increased improvement and satisfaction regarding subjective knee function. Factors other than surgical volume influenced subsequent surgery rates. Patients might benefit from undergoing primary ACLR by high-volume providers.

Estimation Failure Risk by 0.5-mm Differences in Autologous Hamstring Graft Diameter in Anterior Cruciate Ligament Reconstruction: A Meta-analysis

BACKGROUND

Because grafts are made in 0.5-mm increments clinically for anterior cruciate ligament (ACL) reconstruction, it is important to clarify how the failure rate decreases as the diameter increases. Moreover, it is important to know whether even a slight increase in the graft diameter decreases the risk of failure.

HYPOTHESIS

The risk of failure decreases significantly with each 0.5-mm increase in hamstring graft diameter.

STUDY DESIGN

Meta-analysis; Level of evidence, 4.

METHODS

The systematic review and meta-analysis have estimated the diameter-specific failure risk for each 0.5-mm increase in ACL reconstruction using autologous hamstring grafts. We searched for studies describing the relationship between graft diameter and failure rate published before December 1, 2021, in leading databases, such as PubMed, EMBASE, Cochrane Library, and Web of Science, according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. We included studies using single-bundle autologous hamstring grafts to investigate the relationship between failure rate and graft diameter of 0.5-mm intervals with >1-year follow-up. Then, we calculated the failure risk caused by 0.5-mm differences in autologous hamstring graft diameter. Assuming Poisson distribution for the statistical model, we employed an extended linear mixed-effects model in the meta-analyses.

RESULTS

Five studies containing 19,333 cases were eligible. The meta-analysis revealed that the estimated value of the coefficient of diameter in the Poisson model was -0.2357 with a 95% CI of -0.2743 to -0.1971 (P < .0001). With every 1.0-mm increase in diameter, the failure rate decreased by 0.79 (0.76-0.82) times. In contrast, the failure rate increased by 1.27 (1.22-1.32) times for each 1.0-mm decrease in diameter. The failure rate significantly decreased with each 0.5-mm increase in graft diameter in the range of <7.0 to >9.0 mm from 3.63% to 1.79%.

CONCLUSION

The risk of failure decreased correspondingly with each 0.5-mm increase in graft diameter in the range of <7.0 to >9.0 mm. Failure is multifactorial; however, increasing the graft diameter as much as possible to match each patient's anatomic space without overstuffing is an effective precaution that surgeons can take to reduce failures.

Knee-Related Quality of Life Compared Between 20 and 35 Years After an Anterior Cruciate Ligament Injury Treated Surgically With Primary Repair or Reconstruction, or Nonsurgically

BACKGROUND

Quality of life (QoL) is affected up to 5 years after an anterior cruciate ligament (ACL) injury. Knee impairment and osteoarthritis (OA) development increase over time, and this may affect QoL at a long-term follow-up.

PURPOSE

To investigate changes in health- and knee-related QoL between 20 and 35 years after ACL injury and compare it between patients treated with or without ACL surgery, as well as to study how symptomatic OA (SOA) is associated with change in QoL.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Between 1980 and 1983, 139 patients with acute ACL rupture were allocated to surgical or nonsurgical treatment of the ACL. Both groups completed a structured rehabilitation program. Of those patients, 59 were followed for 20 and 35 years after ACL rupture. After 10 crossovers, 33 patients were treated with primary repair or ACL reconstruction, and 26 were treated without ACL surgery. Combined radiographic OA and knee symptoms at 35 years was defined as SOA. QoL was assessed at 20 and 35 years after injury with the Knee injury and Osteoarthritis Outcome Score QoL (KOOS-QoL) subscale (range, 1-100), ACL-QoL questionnaire (total score and 5 subscales; range, 1-100), European QoL-5 Dimensions Questionnaire, and visual analog scale. Results were analyzed with paired and independent-sample t tests and chi-square tests.

RESULTS

Knee-related QoL was impaired at both 20 and 35 years after ACL injury, and differences were dependent on the measurement outcome. In the total cohort, KOOS-QoL did not change but both total ACL-QoL score (7.1 points; 95% CI, 2.2-11.9) and 4 of 5 subscales (5-10 points) decreased (P < .05). No differences were found between treatment groups. QoL decreased overall in patients with SOA, with a 21-point difference within-group change in KOOS-QoL (SOA or non-SOA) between 20 and 35 years of follow-up (P = .001; Cohen d = 1.0).

CONCLUSION

An ACL injury impairs knee-related QoL for up to 35 years, with no difference between treatment approaches (initial repair or later reconstruction compared with nonsurgical treatment). The deterioration decreases with longer follow-up. Clinicians should be aware of differences in QoL depending on the measurement outcome.

Metal interference screw fixation combinations show high revision rates in primary hamstring tendon ACL reconstruction

BACKGROUND

Different fixation methods in anterior cruciate ligament reconstruction (ACLR) have been associated with different revision rates, specifically in the early postoperative period. However, most previous research has either grouped together different fixation types or evaluated femoral-sided fixation or tibial-sided fixation separately. Therefore, the purpose of this study was to determine ACL revision rates for specific combinations of femoral and tibial fixation methods within 2 years of primary hamstring tendon autograft ACLR based on data from the Swedish National Knee Ligament Registry (SNKLR).

METHODS

Patients that underwent primary hamstring tendon autograft ACLR between 2005 and 2018 in the SNKLR were included. The collected data included patient characteristics (age, sex, body mass index [BMI]), activity at time of injury, surgical information (concomitant injuries, time from injury to surgery, fixation types at the femur and tibia), and subsequent revision ACLR. Revision rate within 2 years of the index procedure was chosen, as ACLR fixation is most likely to contribute to ACLR revision within the first 2 years, during graft maturation.

RESULTS

Of the 23,238 included patients undergoing primary hamstring ACLR, 581 (2.5%) underwent revision ACLR within 2 years of the index procedure. Among the combinations used for > 300 patients, the femoral metal interference screw/tibial metal interference screw fixation combination had the highest revision rate followed by metal interference screw/resorbable screw and Endobutton/AO screw fixation combinations, with respective revision rates of 4.0, 3.0, and 3.0%. The lowest revision rate within 2 years of ACLR was found in the Endobutton/metal interference screw with backup Osteosuture fixation combination, used in 433 cases, with a failure rate of 0.9%.

CONCLUSION

Different early ACL revision rates were found across different combinations of femoral and tibial fixation devices within 2 years of primary hamstring tendon autograft ACLR. Metal interference screw fixation, particularly when performed on both the femoral and tibial sides, most frequently resulted in revision ACLR. These findings may be helpful for surgeons in selecting appropriate fixation devices for hamstring ACLR.

LEVEL OF EVIDENCE

IV.

Only 10% of Patients With a Concomitant MCL Injury Return to Their Preinjury Level of Sport 1 Year After ACL Reconstruction: A Matched Comparison With Isolated ACL Reconstruction

BACKGROUND

There is a need for an increased understanding of the way a concomitant medial collateral ligament (MCL) injury may influence outcome after anterior cruciate ligament (ACL) reconstruction.

HYPOTHESIS

Patients with a concomitant MCL injury would have inferior clinical outcomes compared with a matched cohort of patients undergoing ACL reconstruction without an MCL injury.

STUDY DESIGN

Matched registry-based cohort study; case-control.

LEVEL OF EVIDENCE

Level 3.

METHODS

Data from the Swedish National Knee Ligament Registry and a local rehabilitation outcome registry were utilized. Patients who had undergone a primary ACL reconstruction with a concomitant nonsurgically treated MCL injury (ACL + MCL group) were matched with patients who had undergone an ACL reconstruction without an MCL injury (ACL group), in a 1:3 ratio. The primary outcome was return to knee-strenuous sport, defined as a Tegner activity scale ≥6, at the 1-year follow-up. In addition, return to preinjury level of sport, muscle function tests, and patient-reported outcomes (PROs) were compared between the groups.

RESULTS

The ACL + MCL group comprised 30 patients, matched with 90 patients in the ACL group. At the 1-year follow-up, 14 patients (46.7%) in the ACL + MCL group had return to sport (RTS) compared with 44 patients (48.9%) in the ACL group (P = 0.37). A significantly lower proportion of patients in the ACL + MCL group had returned to their preinjury level of sport compared with the ACL group (10.0% compared with 25.6%, adjusted P = 0.01). No differences were found between the groups across a battery of strength and hop tests or in any of the assessed PROs. The ACL + MCL group reported a mean 1-year ACL-RSI after injury of 59.4 (SD 21.6), whereas the ACL group reported 57.9 (SD 19.4), P = 0.60.

CONCLUSION

Patients with a concomitant nonsurgically treated MCL injury did not return to their preinjury level of sport to the same extent as patients without an MCL injury 1 year after ACL reconstruction. However, there was no difference between the groups in terms of return to knee strenuous activity, muscle function, or PROs.

CLINICAL RELEVANCE

Patients with a concomitant nonsurgically treated MCL injury may reach outcomes similar to those of patients without an MCL injury 1 year after an ACL reconstruction. However, few patients return to their preinjury level of sport at 1 year.

Comparison of Improvement in Patient-Reported Knee Function After Revision and Multiple-Revision ACL Reconstruction Compared With Primary ACL Reconstruction

Background

Graft failure after anterior cruciate ligament reconstruction (ACLR) is a debilitating complication often requiring revision surgery. It is widely agreed upon that functional knee outcomes after revision ACLR (r-ACLR) are inferior compared with those after primary reconstruction. However, data are scarce on outcomes after multiple-revision ACLR (mr-ACLR).

Purpose

To compare patient-reported knee function in terms of Knee injury and Osteoarthritis Outcome Score (KOOS) preoperatively and 1-year postoperatively after primary ACLR, r-ACLR, and mr-ACLR and evaluate the pre- to postoperative improvement in KOOS scores for each procedure.

Study Design

Cohort study; Level of evidence, 3.

Methods

Patients from the Swedish National Knee Ligament Registry who underwent their index ACLR between 2005 and 2020 with a minimum age of 15 years at the time of surgery were included in this study. All patients had pre- and postoperative KOOS data. The 1-year postoperative KOOS and the pre- to postoperative changes in KOOS were assessed between patients who underwent primary ACLR and those who underwent subsequent r-ACLR and mr-ACLR.

Results

Of 20,542 included patients, 19,769 (96.2%) underwent primary ACLR, 760 (3.7%) underwent r-ACLR, and 13 (0.06%) underwent mr-ACLR. Patients who underwent r-ACLR had significantly smaller pre- to postoperative changes on all KOOS subscales compared with patients undergoing primary ACLR (P < .0001 for all). Furthermore, patients in the mr-ACLR group had significantly smaller changes in the KOOS-Pain subscale compared with patients in the r-ACLR group (-9 ± 23.3 vs 2.5 ± 18; P = .024).

Conclusion

The study results indicated that while improvement is seen after primary ACLR, r-ACLR, and mr-ACLR, the greatest improvement in functional outcomes is observed after primary ACLR. Patients who underwent at least 1 r-ACLR, specifically mr-ACLR, had lower postoperative outcome scores, indicating that primary ACLR may provide the best chance for recovery after ACL injury.

Quadriceps tendon autograft has similar clinical outcomes when compared to hamstring tendon and bone-patellar tendon-bone autografts for revision ACL reconstruction: a systematic review and meta-analysis

PURPOSE

Research regarding revision anterior cruciate ligament reconstruction (RACLR) with quadriceps tendon (QT) autografts is lacking. The purpose of this study was to perform a systematic review and meta-analysis of RACLR with QT and compare its patient outcomes to RACLR with hamstring tendon (HT) and bone-patellar tendon-bone (BTB) autografts.

METHODS

Adhering to PRISMA guidelines, a search for studies using QT in RACLR was performed within PubMed, Scopus, and CINAHL from database date of inception through December 26, 2022. Primary outcomes sought included: failure rate, Lysholm scores, International Knee Documentation Committee (IKDC) scores, IKDC grades, arthrometric knee side-to-side differences (STSD), pivot shift grade, donor site morbidity, return to sport, visual analog scale (VAS) pain scores.

RESULTS

Nine studies were included consisting of 606 RACLR: 349 QT, 169 HT, and 88 BTB. Overall failure rates were 7.6% QT, 13.3% HT, and 8.7% BTB. Mean weighted Lysholm scores were 85.8 ± 3.8 QT, 82.5 ± 3.8 HT and 86.6 ± 4.5 BTB. IKDC average scores were 82.3 ± 1.6 QT, 80.1 ± 1.7 HT, and 81.7 ± 5.5BTB. Combined rates of IKDC A/B grades were 88.4% and 80.0% for QT and HT, respectively. VAS average scores were 0.9 ± 1.1 QT, 1.4 ± 0.2 HT, and 0.7 ± 0.8 for BTB. Side-to-side difference was reported for QT and HT with average values of 1.7 ± 0.6 mm and 2.1 ± 0.5 mm, respectively. Grade 0 or 1 pivot shifts were reported in 96.2% of QT patients and 91.3% of HT. Donor site morbidity, only reported for QT and HT, was 14.6 ± 9.7% and 23.6 ± 14.1%, respectively. QT resulted in a mean Tegner score of 5.9 ± 1.5 versus HT 5.7 ± 1.5. Rate of return to pivoting sports was 38.0% QT, 48.6% HT, and 76.9% BTB. Across all outcomes, there was no significant difference when comparing QT to HT, QT to BTB, and QT compared to HT and BTB combined.

CONCLUSIONS

RACLR with QT yields satisfactory patient reported outcomes, satisfactory improvement in knee laxity, expected return to sport rates, and has an overall 7.6% failure rate. Outcomes are comparative to those of HT and BTB making it an acceptable graft choice for RACLR. Surgeons should consider using QT autograft for RACLR, especially when other autografts are unavailable.

LEVEL OF EVIDENCE

IV.

Self-reported knee function and activity level are reduced after primary or additional anterior cruciate ligament injury in female football players: a five-year follow-up study

BACKGROUND

Playing football involves a high risk of anterior cruciate ligament (ACL) injuries and these may affect knee function and activity level.

OBJECTIVES

To measure changes in self-reported knee function, activity level, and satisfaction with knee function and activity level in female football players with or without an ACL-reconstructed knee.

METHODS

Female football players, age 19.9 (SD 2.6) years, with either a primary ACL-reconstruction 1.6 (SD 0.7) years after ACL-reconstruction (n = 186) or no ACL injury (n = 113) were followed prospectively for five years. Self-reported data collected at baseline and follow-up included knee function (International Knee Documentation Committee Subjective Knee Form [IKDC-SKF]), activity level (Tegner Activity Scale), and satisfaction with knee function (Likert scale 1=happy; 7=unhappy) and activity level (1-10 scale). Information on any new ACL injury during the follow-up period was collected.

RESULTS

Players with ACL-reconstruction at baseline who either did (n = 56) or did not (n = 130) sustain an additional ACL injury, and players with no injury at baseline who remained injury free (n = 101) had a lower Tegner score at follow-up. Players with additional ACL injury had lower IKDC-SKF score (mean difference: -11.4, 95% CI: -16.0, -6.7), and satisfaction with activity level (mean difference: -1.5, 95% CI: -2.3, -0.7) at follow-up. Players with no additional ACL injury had higher satisfaction with knee function (mean difference: 0.6, 95% CI: 0.3, 0.9) at follow-up. Players with no ACL injury had lower satisfaction with activity level (mean difference: -0.7, 95% CI: -1.1, -0.3) at follow-up. Players with additional ACL injury had larger decreases in all variables measured compared to the two other groups.

CONCLUSION

Primary, and even more so additional, ACL injuries decreased self-reported knee function, activity level, and satisfaction with knee function and activity level in female football players.

Effect of Concomitant Lateral Meniscal Management on ACL Reconstruction Revision Rate and Secondary Meniscal and Cartilaginous Injuries

BACKGROUND

Simultaneous meniscal tears are often present with anterior cruciate ligament (ACL) injuries, and in the acute setting, the lateral meniscus (LM) is more commonly injured than the medial meniscus.

PURPOSE

To investigate how a concomitant LM injury, repaired, resected, or left in situ during primary ACL reconstruction (ACLR), affects the ACL revision rate and cartilaginous and meniscal status at the time of revision within 2 years after the primary ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data for 31,705 patients with primary ACLR, extracted from the Swedish National Knee Ligament Registry, were used. The odds of revision ACLR, and cartilaginous as well as meniscal injuries at the time of revision ACLR, were assessed between the unexposed comparison group (isolated ACLR) and the exposed groups of interest (ACLR + LM repair, ACLR + LM resection, ACLR + LM repair + LM resection, or ACLR + LM injury left in situ).

RESULTS

In total, 719 (2.5%) of the included 29,270 patients with 2 years follow-up data underwent revision ACLR within 2 years after the primary ACLR. No significant difference in revision rate was found between the groups. Patients with concomitant LM repair (OR, 3.56; 95% CI, 1.57-8.10; P = .0024) or LM resection (OR, 1.76; 95% CI, 1.18-2.62; P = .0055) had higher odds of concomitant meniscal injuries (medial or lateral) at the time of revision ACLR than patients undergoing isolated primary ACLR. Additionally, higher odds of concomitant cartilage injuries at the time of revision ACLR were found in patients with LM resection at index ACLR compared with patients undergoing isolated primary ACLR (OR, 1.73; 95% CI, 1.14-2.63; P = .010).

CONCLUSION

The results of this study demonstrated higher odds of meniscal and cartilaginous injuries at the time of revision ACLR within 2 years after primary ACLR + LM resection and higher odds of meniscal injury at the time of revision ACLR within 2 years after primary ACLR + LM repair compared with isolated ACLR. Surgeons should be aware of the possibility of concomitant cartilaginous and meniscal injuries at the time of revision ACLR after index ACLR with concomitant LM injury, regardless of the index treatment type received.

Differences in postoperative knee function based on concomitant treatment of lateral meniscal injury in the setting of primary ACL reconstruction

BACKGROUND

Concomitant lateral meniscal (LM) injuries are common in acute anterior cruciate ligament (ACL) ruptures. However, the effect of addressing these injuries with various treatment methods during primary ACL reconstruction (ACLR) on patient-reported outcomes (PROs) is unknown. Therefore, the purpose of this study was to compare postoperative Knee injury and Osteoarthritis Outcome Score (KOOS) at 2-, 5-, and 10-years after isolated primary ACLR to primary ACLR with various treatment methods to address concomitant LM injury.

METHODS

This study was based on data from the Swedish National Knee Ligament Registry. Patients ≥ 15 years with data on postoperative KOOS who underwent primary ACLR between the years 2005 and 2018 were included in this study. The study population was divided into five groups: 1) Isolated ACLR, 2) ACLR + LM repair, 3) ACLR + LM resection, 4) ACLR + LM injury left in situ, and 5) ACLR + LM repair + LM resection. Patients with concomitant medial meniscal or other surgically treated ligament injuries were excluded.

RESULTS

Of 31,819 included patients, 24% had LM injury. After post hoc comparisons, significantly lower scores were found for the KOOS Symptoms subscale in ACLR + LM repair group compared to isolated ACLR (76.0 vs 78.3, p = 0.0097) and ACLR + LM injury left in situ groups (76.0 vs 78.3, p = 0.041) at 2-year follow-up. However, at 10-year follow-up, no differences were found between ACLR + LM repair and isolated ACLR, but ACLR + LM resection resulted in significantly lower KOOS Symptoms scores compared to isolated ACLR (80.4 vs 82.3, p = 0.041).

CONCLUSION

The results of this study suggest that LM injury during ACLR is associated with lower KOOS scores, particularly in the Symptoms subscale, at short- and long-term follow-up. However, this finding falls below minimal clinical important difference and therefore may not be clinically relevant.

LEVEL OF EVIDENCE

III.

Evaluating the Use of PROMs in Paediatric Orthopaedic Registries

Patient-reported outcome measures (PROMs) provide structured information on the patient's health experience and facilitate shared clinical decision-making. Registries that collect PROMs generate essential information about the clinical course and efficacy of interventions. Whilst PROMs are increasingly being used in adult orthopaedic registries, their use in paediatric orthopaedic registries is not well known. The purpose of this systematic review was to identify the frequency and scope of registries that collect PROMs in paediatric orthopaedic patient groups. In July 2023, six databases were systematically searched to identify studies that collected PROMs using a registry amongst patients aged under 18 years with orthopaedic diagnoses. Of 3190 identified articles, 128 unique registries were identified. Three were exclusively paediatric, 27 were majority paediatric, and the remainder included a minority of paediatric patients. One hundred and twenty-eight registries collected 72 different PROMs, and 58% of these PROMs were not validated for a paediatric population. The largest group of orthopaedic registries collected PROMs on knee ligament injuries (21%). There are few reported dedicated orthopaedic registries collecting PROMs in paediatric populations. The majority of PROMs collected amongst paediatric populations by orthopaedic registries are not validated for patients under the age of 18 years. The use of non-validated PROMs by registries greatly impedes their utility and impact. Dedicated orthopaedic registries collecting paediatric-validated PROMs are needed to increase health knowledge, improve decision-making between patients and healthcare providers, and optimise orthopaedic management.

Bilateral Anterior Cruciate Ligament Reconstruction Using Gracilis and Semitendinosus Graft by Single-Staged Approach

A bilateral anterior cruciate ligament (ACL) tear is one of the rare injuries that is seen in orthopaedics practice. Although few single-staged bilateral ACL ruptures have also been documented, most bilateral ACL ruptures happen on two different occasions. Although there isn't a clear consensus, there have been accounts of both single-staged and two-staged reconstruction of bilateral ACL ruptures in the literature. This case report provides surgeons with options to consider while treating this unusual injury. A 35-year-old woman with bilateral anterior cruciate ligament injuries presented with an MRI of her left knee suggestive of a complete ACL tear with a Medial meniscus tear in the left knee, and an MRI of her right knee showed a complete ACL tear. The patient underwent arthroscopic ACL reconstruction in a single stage for both knees. Six months after her surgery, she had met all the rehabilitation goals and was cleared to resume her daily activities. The patient preoperatively had a visual analogue scale (VAS) score of 8, and postoperative assessment, her VAS score reduced to 2. ACL reconstruction in one stage and two stages were the surgical treatment modalities described in the literature. Concurrent rehabilitation of both ACL repairs is more economical, reduces hospital stay, and helps in early recovery, but it may result in severe quadriceps deconditioning. Double-staged surgeries are less demanding, with a shorter duration of surgery that can be performed by a less experienced surgeon. As single-staged bilateral ACL reconstruction is a less expensive option that reduces hospital stays and aids in early recovery for this rare patient population, it may be a great therapy option compared to two-staged bilateral ACL reconstruction.

Improvement Trajectories in Patient-Reported Outcomes Between Males and Females After Anterior Cruciate Ligament Reconstruction

CONTEXT

Patient-reported outcomes (PROs) are used to track recovery and inform clinical decision-making after anterior cruciate ligament reconstruction (ACLR). Whether sex influences the trajectory of improvements in PROs over time post-ACLR remains unclear.

OBJECTIVES

To (1) examine the effect of sex on the association between months post-ACLR and Knee injury and Osteoarthritis Outcome Score (KOOS) Quality of Life (QOL) scores in individuals with ACLR and (2) assess sex differences in the KOOS QOL score at selected timepoints post-ACLR.

DESIGN

Cross-sectional study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 133 females (20± 3 years) and 85 males (22 ± 4 years) within 6 to 60 months of primary, unilateral ACLR.

MAIN OUTCOME MEASURE(S)

The KOOS QOL was completed at a single follow-up timepoint post-ACLR. A multivariate linear regression model was calculated to assess the interaction of sex on the association between months post-ACLR and KOOS QOL score. Sex-specific linear regression models were then used to predict KOOS QOL estimated marginal means at each clinical timepoint (6, 12, 24, 36, 48, and 60 months post-ACLR) and compare the sexes.

RESULTS

In the primary model (R2 = 0.16, P < .0001), a significant interaction existed between sex and time post-ACLR (β = -0.46, P < .01). Greater months post-ACLR were associated with better KOOS QOL scores for males (R2 = 0.29, β = 0.69, P < .001); months post-ACLR was a weaker predictor of KOOS QOL scores for females (R2 = 0.04, β = 0.23, P < .02). Estimated marginal means for KOOS QOL scores were greater for males than females at 36 months (t210 = 2.76, P < .01), 48 months (t210 = 3.02, P < .01), and 60 months (t210 = 3.09, P = .02) post-ACLR.

CONCLUSIONS

Males exhibited PRO improvement post-ACLR as the months post-ACLR increased, whereas females did not demonstrate the same magnitude of linear increase in KOOS QOL score. Females may require extended intervention to improve clinical outcomes post-ACLR and address a plateau in QOL score.

Current trends in graft choice for primary anterior cruciate ligament reconstruction - part II: In-vivo kinematics, patient reported outcomes, re-rupture rates, strength recovery, return to sports and complications

Postoperative patient satisfaction after anterior cruciate ligament reconstruction (ACL-R) is influenced mainly by the degree of pain, the need for reoperation, and functional performance in daily activities and sports. Graft choice has shown to have an influence on postoperative outcomes after ACL-R. While patient reported outcomes measurements do not differ between graft options, evidence shows that normal knee kinematics is not fully restored after ACL-R with an increase in postoperative anterior tibial translation (ATT). Postoperative graft rupture rates seem to favor bone-patella-tendon-bone (BPTB) and quadriceps tendon (QT) autografts over HT or allografts. While return to sports rates seem comparable between different graft types, postoperative extensor strength is reduced in patients with BPTB and QT whereas flexion strength is weakened in patients with HT. Postoperative donor site morbidity is highest in BPTB but comparable between HT and QT. With all graft options having advantages and drawbacks, graft choice must be individualized and chosen in accordance with the patient.

New or Recurrent Knee Injury, Physical Activity, and Osteoarthritis Beliefs in a Cohort of Female Athletes 2 to 3 Years After ACL Reconstruction and Matched Healthy Peers

BACKGROUND

At 2 to 3 years after anterior cruciate ligament reconstruction (ACLR), the relationship between known modifiable osteoarthritis (OA) risk factors and recurrent knee injury is unknown. This study aimed to determine the odds of new or recurrent traumatic knee injury in a cohort of young female athletes with ACLR 2 to 3 years postsurgery compared with healthy control participants. Secondary objectives were to explore the relationships of moderate and vigorous physical activity (MVPA) and body mass index (BMI) with knee injury, and to document self-reported MVPA satisfaction and beliefs about OA.

STUDY DESIGN

Prospective cohort.

LEVEL OF EVIDENCE

Level 2.

METHODS

A total of 51 female athletes with unilateral ACLR 1 to 2 years previously and 51 age and sport-matched control participants underwent assessment of MVPA (GT3X accelerometers) and BMI. One year later, participants self-reported knee injuries. Bivariable conditional logistic regression explored the association between knee injury, MVPA, and BMI in each group (injury/control).

RESULTS

At 1-year follow-up (n = 101), 19.6% of the injured cohort and 6.0% of control participants sustained a new or recurrent knee injury. The odds of knee injury for the injury group increased 7-fold over controls [odds ratio (OR) = 7.00 (95% CI = 0.86, 56.90)], although this was not statistically significant. The OR for MVPA was 0.98 (95% CI = 0.93, 1.03) and BMI was OR = 1.24 (95% CI = 0.85, 1.82). Half (56.0%) of injury participants and 66% of controls were satisfied with their MVPA; 81.6% of injury participants believed they had increased knee OA risk compared with someone who had never had a knee injury.

CONCLUSION

In the 2 to 3 years after ACLR, 1 in 5 young female athletes had a new or recurrent knee injury. Based on the point estimate, injured participants were more likely to suffer a traumatic knee injury than matched control participants. MVPA and BMI were not associated with increased odds of knee injury.

CLINICAL RELEVANCE

Clinicians should be encouraged to have in-depth conversations with female athletes with previous ACLR regarding enjoyable and sustainable MVPA participation to promote long-term joint health.

Scoping Review on ACL Surgery and Registry Data

PURPOSE OF REVIEW

To present an overview of registry-based anterior cruciate ligament (ACL) research, as well as provide insight into the future of ACL registries.

RECENT FINDINGS

During the past decades, the ACL registries have had an important role in increasing our understanding of patients with ACL injuries and their treatment. The registry data has deepened our understanding of factors that have been associated with an increased risk of sustaining an ACL injury and for evaluation of treatment factors and their impact on patient-related outcomes. Recently, registry-based ACL research using artificial intelligence (AI) and machine learning (ML) has shown potential to create clinical decision-making tools and analyzing outcomes. Thus, standardization of collected data between the registries is needed to facilitate the further collaboration between registries and to facilitate the interpretation of results and subsequently improve the possibilities for implementation of AI and ML in the registry-based research. Several studies have been based on the current ACL registries providing an insight into the epidemiology of ACL injuries as well as outcomes following ACL reconstruction. However, the current ACL registries are facing future challenges, and thus, new methods and techniques are needed to ensure further good quality and clinical applicability of study findings based on ACL registry data.

Evidence for isokinetic and functional testing in return to sport decisions following ACL surgery

The rupture and reconstruction of the anterior cruciate ligament (ACL) of the knee are associated with an increased risk of functional instability, a reduction in sports performance, and a higher risk of future additional injuries. Competitive athletes who participate in sports that require pivoting, cutting, and jumping are at particularly high risk for ACL rupture. The return to sport progression continuum after surgery includes sports-specific rehabilitation, evaluation of strength and function, gradual participation in exercise training with progressively challenging activities in the field of play, participation in sports at a lower level, and finally a return to preinjury-level sports competition. This narrative review evaluates the evidence that supports the use of quadriceps and hamstrings isokinetic strength testing and sports-specific functional skills assessments to evaluate progress with rehabilitation after ACL surgery. Strength evaluations, hop tests, agility tests, and the limb symmetry index are described, as well as the associations of quadriceps and hamstrings muscle strength and functional test results with successful return to sports and the risk of ACL graft rupture and contralateral knee injuries. Suggestions for future research directions are presented including the importance of presurgery testing, standardization of test batteries, and comparison of test results with normative data.

Biomechanics of hamstring tendon, quadriceps tendon, and bone-patellar tendon-bone grafts for anterior cruciate ligament reconstruction: a cadaveric study

PURPOSE

The three most commonly used autografts for anterior cruciate ligament reconstruction (ACL) are: bone-patellar tendon-bone (BTB), hamstring tendons (HT), and quadriceps tendon (QT). A cadaveric study was performed to determine if there were any differences in mechanical and structural properties under biomechanical testing.

METHODS

Twenty-seven graft specimens were harvested from 9 human cadaveric legs. Mean donor age was 75.2 years (range 53-85 years). Twenty-two specimens (8 HT, 7 QT, and 7 BTB) completed cyclic preconditioning from 50 to 800 N for 200 cycles and a load to failure test at an extension rate of 1 mm/s. Structural and mechanical properties of BTB, HT, and QT grafts were compared using a one-way ANOVA and Tukey's honest significant difference.

RESULTS

There was no difference in the ultimate load to failure (N) across all 3 graft types (p = 0.951). Quadriceps tendon demonstrated greater cross-sectional area (mm²) when compared to both HT and BTB (p = 0.001) and was significantly stiffer (N/mm) than HT but not BTB (p = 0.004). Stress (N/mm²) of the HT at ultimate load was greater than QT but not BTB (p = 0.036). Elastic modulus (MPa) of HT was greater than both QT and BTB (p = 0.016).

CONCLUSION

There was no difference in the ultimate load to failure of BTB, HT, and QT grafts harvested from the same specimens. All 3 grafts had similar loads to failure with a significant increase in stiffness when compared to the native ACL. Furthermore, QT demonstrated more favourable structural properties compared to HT and BTB with greater cross-sectional area to both HT and BTB and greater stiffness compared to HT.

Revision anterior cruciate ligament reconstruction and outcomes with different autografts in a population with kneeling customs

OBJECTIVES

This study was designed to evaluate, compare the mid-term functional outcome of revision anterior cruciate ligament reconstruction (ACLR) using different autografts and assess the cause of failure of primary ACLR in an Omani population with kneeling customs.

MATERIALS AND METHODS

Patients with failed primary ACLR who underwent revision ACLR using autografts were included in this retrospective study. The cause of primary ACLR failure and the functional outcome was assessed using the Tegner-Lyholm knee score and compared among bone patella tendon-bone (BPTB), quadriceps tendon (QT), semitendinosus gracilis (STG) autografts used.

RESULTS

One hundred two patients (102 male) were included in the study with a minimum follow-up of 2 years. Thirty-one patients underwent revision with BPTB, 34 with STG and 19 with QT autografts. Majority of the patients (70.23%) achieved good-to-excellent functional outcome based on their Tegner-Lysholm scores. The functional outcome of different autografts was comparable to each other based on Kruskal-Wallis test. The causes of primary ACLR failure were failure due to trauma in 58.33% of patients, technical failure in 22.61% of patients, and nontraumatic failure in 19.04% of patients.

CONCLUSIONS

The functional outcome of revision ACLR in this Middle Eastern Asian Omani population was good-to-excellent, with the patients experiencing no difficulty in performing activities of daily living, including kneeling activities. The outcome of different autografts, BTPB, QT, STSG is similar in high knee flexion patients with no autograft found to be superior. The findings of this study add to the literature on functional outcomes after primary and revision ACLR in a customary kneeling population.

LEVEL OF EVIDENCE III

Superior Outcome of Early ACL Reconstruction versus Initial Non-reconstructive Treatment With Late Crossover to Surgery: A Study From the Swedish National Knee Ligament Registry

BACKGROUND

Although comparable clinical and functional outcomes have been reported after nonsurgical and surgical anterior cruciate ligament (ACL) treatment, few studies have investigated the effects of early versus late ACL reconstruction with initial rehabilitation.

PURPOSE

To determine patient-reported knee function in patients who initially undergo nonreconstructive treatment after an ACL injury but who later choose to undergo ACL reconstruction as compared with (1) patients undergoing ACL reconstruction close to the index injury and (2) patients treated nonreconstructively at 1 to 10 years of follow-up.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Results from the Knee injury and Osteoarthritis Outcome Score (KOOS) were extracted from the Swedish National Knee Ligament Registry for patients treated with nonreconstruction, early ACL reconstruction, and initial nonreconstruction but subsequent ACL reconstruction (crossover group). The KOOS₄ (a mean of 4 KOOS subscales) was analyzed cross-sectionally at baseline and at the 1-, 2-, 5-, and 10-year follow-ups. Additionally, the Patient Acceptable Symptom State (PASS) was applied to all KOOS subscales from baseline to the 10-year follow-up.

RESULTS

A total of 1,074 crossover, 484 nonreconstruction, and 20,352 early ACL reconstruction cases were included. The crossover group reported lower KOOS₄ values than the group undergoing early ACL reconstruction at baseline and at all follow-ups (mean difference [95% CI]): baseline, -6.5 (-8.0 to -5.0); 1 year, -9.3 (-10.9 to -7.7); 2 years, -4.8 (-6.3 to -3.2); 5 years, -6.1 (-8.8 to -3.4); and 10 years, -10.9 (-16.3 to -5.2). Additionally, a smaller proportion of the crossover cohort achieved a PASS on KOOS subscales at baseline and through the 1-, 2-, 5-, and 10-year follow-ups as compared with the early ACL reconstruction cohort. No differences were observed between crossover and nonreconstruction cases on either the KOOS₄ or the PASS at any follow-up.

CONCLUSION

A greater proportion of patients treated with early ACL reconstruction reported acceptable knee function and superior overall knee function as compared with patients who decided to cross over from nonreconstructive treatment to ACL reconstruction.

Patient-Reported Outcome, Return to Sport, and Revision Rates 7-9 Years After Anterior Cruciate Ligament Reconstruction: Results From a Cohort of 2042 Patients

BACKGROUND

Long-term patient-reported outcome measures (PROMs), rates of return to sport, and revision risk after anterior cruciate ligament (ACL) reconstruction (ACLR) are not well understood.

PURPOSE

To provide long-term follow-up of PROMs, return-to-sport rates, and revision rates after ACLR and to identify predictors for poor outcome.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A total of 2042 patients were included in an institutional ACL registry (2009-2013) and longitudinally followed. PROMs were completed preoperatively and at all follow-up time points. Questions regarding return to sport and knee stability were completed at final follow-up. Predictors for poor outcome on the International Knee Documentation Committee (IKDC) score were estimated in a regression model incorporating risk factors such as patient characteristics, graft choice, and concomitant injuries. Revision rates and risk of subsequent non-ACL surgeries were calculated.

RESULTS

Autografts were used in 76% of the patients (patellar tendon, 62%; hamstring grafts, 38%). Allografts were used in 24% of patients. The questionnaires were returned by 1045 (51.2%) patients at a mean of 7.2 years (range, 5.0-9.8 years) after surgery. Improvements in IKDC score of >30 points were sustained for all patient categories. The strongest predictor for lesser improvement in IKDC score was a cartilage lesion >2 cm2 identified during surgery. Male sex and college education completion were associated with improved IKDC scores. Meniscal lesions did not predict change) in the IKDC score. A total of 69% of patients had returned to sport after 8.1 years (range, 6.7-9.8 years). The main reason for not returning to sport was fear of reinjury. The revision rate was 7.2% after 9 years (range, 8-11 years), 13% of patients needed subsequent ipsilateral non-ACL surgery, and 6% underwent contralateral ACLR. The absence of a meniscal tear, younger age, and male sex were predictors for revision. Graft choice did not predict PROM results or revision risk.

CONCLUSION

Improvements in IKDC scores were sustained 7 years after ACLR. The strongest predictor for poor outcome was a cartilage lesion >2 cm2. Patients can expect a 70% return-to-sport rate and an 87% chance of their knee feeling stable during daily and athletic activities after 8 years. Young male patients have better PROM scores but a higher risk of revision. There is a 26% chance of subsequent knee surgery within 9 years, including a revision rate of 7%, subsequent non-ACL surgery to the operated knee in 13%, and a 6% chance of contralateral ACLR.

Age, time from injury to surgery and hop performance after primary ACLR affect the risk of contralateral ACLR

PURPOSE

To evaluate factors affecting the risk of contralateral anterior cruciate ligament reconstruction (ACLR) within 5 years of primary ACLR.

METHODS

Primary ACLRs performed at Capio Artro Clinic, Stockholm, Sweden, during the period 2005-2014, were reviewed. The outcome of the study was the occurrence of contralateral ACLR within 5 years of primary ACLR. Univariable and multivariable logistic regression analyses were employed to identify preoperative [age, gender, body mass index (BMI), time from injury to surgery, pre-injury Tegner activity level], intraoperative [graft type, medial meniscus (MM) and lateral meniscus (LM) resection or repair, cartilage injury] and postoperative [limb symmetry index (LSI) for quadriceps and hamstring strength and single-leg-hop test performance at 6 months] risk factors for contralateral ACLR.

RESULTS

A total of 5393 patients who underwent primary ACLR were included. The incidence of contralateral ACLR within 5 years was 4.7%. Univariable analysis revealed that age ≥ 25 years, BMI ≥ 25 kg/m², time from injury to surgery ≥ 12 months and the presence of a cartilage injury reduced the odds, whereas female gender, pre-injury Tegner activity level ≥ 6, quadriceps and hamstring strength and a single-leg-hop test LSI of ≥ 90% increased the odds of contralateral ACLR. Multivariable analysis showed that the risk of contralateral ACLR was significantly affected only from age ≥ 25 years (OR 0.40; 95% CI 0.28-0.58; P < 0.001), time from injury to surgery ≥ 12 months (OR 0.48; 95% CI 0.30-0.75; P = 0.001) and a single-leg-hop test LSI of ≥ 90% (OR 1.56; 95% CI 1.04-2.34; P = 0.03).

CONCLUSION

Older age (≥ 25 years) and delayed primary ACLR (≥ 12 months) reduced the odds, whereas a symmetrical (LSI ≥ 90%) 6-month single-leg-hop test increased the odds of contralateral ACLR within 5 years of primary ACLR. Knowledge of the factors affecting the risk of contralateral ACLR is important when it comes to the appropriate counselling for primary ACLR. Patients should be advised regarding factors affecting the risk of contralateral ACLR.

LEVEL OF EVIDENCE

Level III.

Failed meniscal repair increases the risk for osteoarthritis and poor knee function at an average of 9 years follow-up

PURPOSE

The purpose of this study was to determine the effect of meniscal repair on OA in the knee joint and patient-related outcomes.

METHODS

Three-hundred and sixteen meniscal repairs performed between 1999 and 2011 were analysed. Patient-related outcome measures were assessed through mailed questionnaires including KOOS, Lysholm score and Tegner activity level. Patients answering the questionnaires were encouraged to perform a radiographic evaluation with Rosenberg views, assessed according to Kellgren-Lawrence (KL) classification. The primary endpoint was to determine the effect of meniscal repair on the development of radiographic OA defined as a KL grade 2 or more.

RESULTS

Mean follow-up time was 9.3 years (SD 3.6), 162 (51%) patients answered the questionnaires, and 86 patients completed the X-ray. The odds ratio for OA with a failed meniscus repair was 5.1 (p = 0.007) adjusted for gender and age at time of follow-up. KOOS showed a clinically important difference in the sport and recreation subscale (p = 0.041).

CONCLUSIONS

There was an increased risk for OA in the affected compartment with a failed meniscus fixation. This supports the fact that the meniscus is an important protector of the cartilage in the knee. The meniscus injury affects the long-term health-related quality of life according to KOOS and in light of this study we recommend repair of a torn meniscus whenever possible.

LEVEL OF EVIDENCE

III.

Comparison of Clinical Outcomes after Revision Anterior Cruciate Ligament Reconstruction using a Bone-patellar Tendon-bone Autograft and that Using a Double-Bundle Hamstring Tendon Autograft

PURPOSE

 The purpose of this study was to compare clinical outcomes between revision anterior cruciate ligament reconstruction (ACLR) using a bone-patellar tendon-bone (BPTB) autograft and that using a double-bundle hamstring tendon (HT) autograft.

METHODS

 Consecutive cases of revision ACLRs were reviewed. The Lysholm knee scale and Knee Osteoarthritis Outcome Score (KOOS) were recorded at the final follow-up. The pivot shift test, Lachman test, and anterior knee laxity measurement using an arthrometer were evaluated before revision ACLR and at final follow-up. Contralateral knee laxity was also evaluated, and side-to-side differences noted. The Lysholm knee scale, KOOS, the pivot shift test, Lachman test, and anterior knee laxity were compared between HT versus BPTB autograft recipient groups using the Mann-Whitney test or the t-test.

RESULTS

 Forty-one patients who underwent revision ACLR and followed up for at least 2 years were included. The graft source was a BPTB autograft in 23 patients (BPTB group) and a double-bundle HT autograft in 18 patients (HT group). The mean postoperative follow-up period was 44 ± 28 months in the BPTB group and 36 ± 18 in the HT group (p = 0.38). The HT group had significantly higher KOOS in the pain subscale (less pain) than the BPTB group at the final follow-up (BPTB group 84.2 vs. HT group 94.4; p = 0.02). The BPTB group showed significantly smaller side-to-side difference in anterior knee laxity (superior stability) than the HT group (0.3 vs. 2.6 mm; p < 0.01). The percentage of patients with residual anterior knee laxity in the BPTB group was significantly lower than that in the HT group (9.5% vs. 46.7%; odds ratio, 8.3; p = 0.02).

STUDY DESIGN

 This was a level 3 retrospective study.

CONCLUSION

 Revision ACLR with a BPTB autograft was associated with superior results regarding restoration of knee joint stability as compared with that with a double-bundle HT autograft, whereas double-bundle HT autograft was superior to BPTB autograft in terms of patient-reported outcomes of pain. The rest of the patient-reported outcomes were equal between the two groups.